﻿// RankingSejmowy 1.0 - Polish parliment statistics for the masses.
// Copyright (C) 2010 Jarosław Dubrownik
//  
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//  
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//  
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
using System;
using System.Diagnostics;
using System.IO;
using System.Text;
using RankingSejmowy.Model.Import;

namespace RankingSejmowy.BLL.Import.Spider.Downloaders
{
    public class DiskPageCache : IPageCache
    {
        private readonly string _cacheDir;
        private readonly Encoding _encoding;

        public DiskPageCache(string cacheDir, Encoding encoding)
        {
            _cacheDir = cacheDir;
            _encoding = encoding;
        }

        #region IPageCache Members

        public bool IsPageInCache(Uri uri)
        {
            Debug.Assert(uri != null);
            var hashCode = uri.GetHashCode();
            var path = GetFilePath(hashCode);
            return File.Exists(path);
        }

        public DownloadedPage GetPageFromCache(Uri uri)
        {
            Debug.Assert(uri != null);
            var path = GetFilePath(uri.GetHashCode());
            var page = new DownloadedPage(_encoding);
            page.LocalFile = path;
            return page;
        }

        public void SavePageInCache(DownloadedPage page)
        {
            Debug.Assert(page != null);
        }

        public string GetFilePath(int hashCode)
        {
            return Path.Combine(_cacheDir, string.Format("{0}.html", hashCode));
        }

        #endregion
    }
}